Grid-Based Risk Modeling:

A Standards ApproachTalbot Brooks, Director, Center for Interdisciplinary Geospatial Information

Technologies, Delta State University

Lightning Talk Presentation

Grid-Based Risk Modeling: A Standards Approach

Talbot Brooks, DirectorCenter for Interdisciplinary Geospatial

Information TechnologiesDelta State University

tbrooks@deltastate.edu662-588-8649

OR: Saving the World One Grid Square at a Time

Dedicated to Ezra Boyd

Overview

• Geospatial standards

• Why use grid coordinates?

• Introduction to the US National Grid

• Standardizing maps

• Plotting point positions

• USNG as an area system for analysis

Background: Standards Are Important

Maryland Digital Cultural Heritage Project at http://www.mdch.org/fire/#

In those days, the thread on fire hydrants and fire hoses was not standardized; each county and city had its own kind of thread. When the first out-of-town firefighters rushed from Washington to help, they could do little because hoses from their apparatus could not hook to Baltimore’s hydrant system or local fire trucks…

Fire departments learned that they needed to standardize when Baltimore burned in 1904.

331 Years of Experience in the US

• Emergency services are standards based organizations– Standard of care– Interoperability/interchangeability– Organizational consistency (NIMS/ICS)– Scalability– Continuity of operations

• When the incident occurs IS NOT the time for innovation

George Washington was a volunteer firefighter with Friendship Veterans Fire Co.

Geospatial Standards

• Colors

• Symbols

• Scale

• Coordinate system

• Projection

• Page size

Office of Management and Budget Circular A-16 (rev. 2002) mandates the coordination of geospatial information and technologies among Federal

agencies through the Federal Geographic Data Committee (FGDC).

Map of Australia, pet rock, or “other”?http://www.abc.net.au/rural/content/2009/s2742168.htm

Standards Bodies

• Federal Geographic Data Committee

– http://www.fgdc.gov

• Open Geospatial Consortium

– http://www.opengeospatial.org

• ANSI and ISO for paper sizes

• US National Grid and the National Search and Rescue Committee– Search “NSARC” and “Georeferencing”

OGC’s Carl Reed was thereto tell Roger Tomlinson how to format the data

when he “invented” GIS...

A number of people here are not seeing this presentation as intended.

Are they seeing your maps?

Will you bet your life on it?

Approximately 10% of the male population is red/green color blind.

“Can you do that GSI stuff?”

• On 27 August 2005 I was tasked by the Bolivar County, MS Office of Emergency Management to find 2-4 people with solid computer skills to respond to the Mississippi Emergency Management Agency’s Emergency Operations Center in Jackson to help prepare written documents in support of the Hurricane Katrina operation.

• We were soon tasked by MEMA to help provide map support using “that GSI stuff” for emergency responders and decision makers.

• One of the very first products we were tasked with making was a map for search and rescue. The specifications were that it should contain streets with a 1-mile x 1-mile grid squares that could be uniquely addressed. The extent of the map should cover the three coastal counties (Jackson, Harrison, and Hancock).

So we made 250 of these and had them laminated and sent to the field…

Two days later…

• Katrina had made landfall and the devastation exceeded most expectations

• The search area was expanded to include Stone, Lincoln, George, and Pearl River counties.

• I realized very quickly that I had screwed up. How was I to expand the map to encompass the new search area without altering the grid ID’s being used already?

How do you expand this north and west?

I’ll use PLSS – what genius! (NOT!)

Maryland Trooper 2

NTSB Report on Trooper 2

• National Transportation and Safety Board (NTSB) report

• Highlights confusion about coordinates“…The shift supervisor relied on ADW tower controllers or SYSCOM DO to provide him with

the last known location of the helicopter. However, he said that he did not plot the coordinates that the SYSCOM DO gave him because he did not know what the coordinates meant.”

• The shift supervisor relayed the coordinates to the PG County dispatcher, adding that the location of the coordinates were approximately two nautical miles SW of FedEx field

• He did not indicate the numbers were in the form of degrees, minutes, seconds

NTSB Report on Trooper 2 (cont'd.)

• Patrol personnel plotted coordinates using an online mapping program

• Dispatchers assumed

coordinates were in form of

degrees, decimal of degrees

(normally used)

• Crash site was actually located

near Calvert Cliffs, Maryland

(almost 30 miles away)

Grid Coordinate Systems

• Grid coordinates use a measured distance from a known set of reference lines for measuring location

• The standardized grid coordinate system used in the United States is called the US National Grid (USNG)– It is the only coordinate system recognized as a standard by the

Federal Geographic Data Committee, the standards body for geospatial technologies in the US

• The basic unit of measure used is the meter

Recommended solution using

US National Grid to create 1km

x 1km grid squares (contact DSU

for procedure as it is involved and

not straight forward – especially

when working at zone junctions,

but still preferable to any other

lat/long or other grid system.

The 1km x 1km grids may be

used as the basis for 4km x 5km

map pages (ideal for 8.5” x 11”

printing). Because each page is

based on USNG, each page may

be assigned both a local page

number and a universally unique

and standardized USNG page

number.

Sample USNG-based map

Book page created using

4km x 5km assemblies of

1km x 1km USNG grids

with layers for critical infra-

structure. Background

polygon layer is Electric

utility Service Areas. Note

that both a local page number

and USNG page number are

provided.

Orientation to the USNG Format

Water Tank at grid: 16R BU 1028 0976

100,000-m Square ID

USNG format: 16R BU 1028 0976

Grid Zone Designation (GZD)(6° lat x 8° longitude quad)

Easting Northing

Grid Coordinates

Read right then up

08/27/98

UTM/USNG Grid Zone Designations

126° 120°

114°

108°

102°

96° 90° 84° 78°

72°

66°

1011 12 13 14 15 16 17 18

19

24°N

32°N

40°N

48°N

15R

S

R

U

T

MGRS Grid Zone Designations

How to read the USNG…

16R

Read right, then up.

Pumping Station: 16R BU 1028 0976 (NAD 83)

90°W

32°N32°N

15S

15R

16S

16R35003500

36003600

34003400

33003300

20070060050040032003200

15R 16R

YN BT

15R 16R

Pumping Station: 16R BU 1028 0976

Read right,then up.

3310

3311

Task:Locate the Water Tank at 1249 1084

Read right, and up.

3310

3311

SolutionLocate the Water Tank at 1249 1084

Slide 4-33

Read right, and up.

3310

3311

SolutionLocate the Water Tank at 1249 1084

Slide 4-34

1249

1084

Read right, and up.

USNG as Area Management/Masking Tool

• Grid squares may be referred to by the coordinates representing the lower-left corner

• Number of digits expresses the size of the grid square

• May be used for

– Area reference

– Aggregator for features

– Analysis grid

Example 1: Poisson Distribution and Tornados

P(x) =e-l lx

x!

where l is the average numberof things in a unit (time or area)

l = 12/4 = 3

P(5) = 2.71828–3*35 / (5*4*3*2*1) = 0.1008

P(2) = 2.71828–3*32 / (2*1) = 0.2240

Tornados 1950-2002

BolivarCounty

Time for a Tornado Shelter!

P(x) =e-l lx

x!

P(1) =e-.12 0.121

1

P(1) = .14

Example: Aggregation and Hotspots

Example: Risk Modeling

MapAlgebra

Bottom Line: Use Standards.Maps for use during a crisis or an emergency are not

for you. They are for those dealing with this…

Waveland, MS after Hurricane Katrina